How to unite/merge two colonies
There comes a time when it is beneficial to the bees, or the beekeeper, to join two colonies together. This may be to save the bees in a colony, which is hopelessly queenless, or to cull a queen with undesirable traits, or to save equipment, or simply to reduce stocks. This is a relatively simple operation, requiring the minimum equipment.
Bees will not unite naturally for two basic reasons.
- They can recognise by smell any intruder who is not a member of their colony.
- A large influx of intruders would immediately put them in defensive mode, resulting in excessive fighting and deaths.
For uniting to be successful therefore, it must be done in such a way as to disguise the odour, and reduce the risk of putting the bees on the defensive.
There are many suggested ways of doing this, including the use of talcum powder or flour, water or sugar syrup sprays, or shaking all the bees in a heap in front of the hive, and letting them run in together, in the hope that this will neutralise the odour. All these methods are either messy or violently disruptive to the bees. The simplest and most successful method involves the use of a sheet of newspaper.
The principal is to place one colony on top of another separated only by newspaper. The bees will chew through the paper and unite, but this will probably take at least twenty-four hours, by which time the colony odours will be neutralised, and the bees will have had time to calm down and are no longer in a defensive attitude.
The hives to be united should be prepared during the day, when most of the flying bees are away from the hive, and the actual uniting done in the evening when all is quiet. The best time of year to unite is in early autumn, after the honey crop has been removed. It can be achieved with supers in place, but they are an added complication. If both colonies are queen right, the decision must be taken which queen to retain.
There is sometimes a “cop out” by beekeepers at this stage, not wanting to kill off perhaps a perfectly good queen, so the two colonies are united leaving the queens to “fight it out”. This is not a good practice, as although the strongest queen is usually the victor, quite often she receives injury during the confrontation.
Much better to find and destroy the unwanted queen before uniting. The colony without a queen should always be united on top of the queen right colony, not the other way around. It is therefore necessary to check and if necessary clean the bottoms of the frames in the queenless colony. As modern hive floors are deeper than a bee space, the bees are prompted to build brace comb under the bottom bars. If these are then placed on top of a sheet of newspaper, the paper will be broken, rendering the operation futile, or the frames will be pushed up, thereby raising the crown board.
Once the colony, which is to be united, has been prepared, it can be closed down until the evening, and attention turned to the receiving colony. All that is necessary here is to check that they are in fact queen right, and scrape off the top bars of the frames to provide a smooth surface for the newspaper to rest on. A single sheet of newspaper is then applied and held in place by a couple of drawing pins, or by covering with a queen excluder. The crown board and roof can then be replaced, and the hive left until the evening.
In the evening, when the bees have finished flying for the day, the roof and crown board are quietly removed. The bees are not disturbed as they are covered by the newspaper. The second hive is then quietly released from its floor, and gently placed over the newspaper. The united hive should be left completely alone for at least two days, or until crumbs of chewed up newspaper can be seen being ejected at the entrance. The colony can then be inspected, and combs moved around to place all the brood in one area, or the brood in the upper chamber simply left to emerge, after which this brood chamber can be removed.